Modeling the Relationships Among Late-Life Body Mass Index, Cerebrovascular Disease, and Alzheimer’s Disease Neuropathology in an Autopsy Sample of 1,421 Subjects from the National Alzheimer’s Coordinating Center Data Set

Article type: Research Article

Authors: Alosco, Michael L.^{a; b; 1} | Duskin, Jonathan^{a; 1} | Besser, Lilah M.^c | Martin, Brett^{a; d} | Chaisson, Christine E.^{a; d} | Gunstad, John^e | Kowall, Neil W.^{a; b; f; g} | McKee, Ann C.^{a; b; f; h; i} | Stern, Robert A.^{a; b; j} | Tripodis, Yorghos^{a; k; *}

Affiliations: [a] Boston University Alzheimer’s Disease and CTE Center, Boston University School of Medicine, Boston, MA, USA | [b] Department of Neurology, Boston University School of Medicine, Boston, MA, USA | [c] National Alzheimer’s Coordinating Center, University of Washington, Seattle, WA, USA | [d] Data Coordinating Center, Boston University School of Public Health, Boston, MA, USA | [e] Department of Psychological Sciences, Kent State University, Kent, OH, USA | [f] Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, MA, USA | [g] Neurology Service, VA Boston Healthcare System, Boston, MA, USA | [h] VA Boston Healthcare System, U.S. Department of Veteran Affairs, Boston, MA, USA | [i] Department of Veterans Affairs Medical Center, Bedford, MA, USA | [j] Departments of Neurosurgery and Anatomy & Neurobiology, Boston University School of Medicine, Boston, MA, USA | [k] Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA

Correspondence: [*] Correspondence to: Yorghos Tripodis, PhD, Department of Biostatistics, Boston University, 801 Massachusetts Ave, Crosstown Center, CT312, Boston, MA 02118, USA. Tel.: +1 617 638 5844; E-mail: yorghos@bu.edu.

Note: [1] These authors contributed equally to this work.

Abstract: The relationship between late-life body mass index (BMI) and Alzheimer’s disease (AD) is poorly understood due to the lack of research in samples with autopsy-confirmed AD neuropathology (ADNP). The role of cerebrovascular disease (CVD) in the interplay between late-life BMI and ADNP is unclear. We conducted a retrospective longitudinal investigation and used joint modeling of linear mixed effects to investigate causal relationships among repeated antemortem BMI measurements, CVD (quantified neuropathologically), and ADNP in an autopsy sample of subjects across the AD clinical continuum. The sample included 1,421 subjects from the National Alzheimer’s Coordinating Center’s Uniform Data Set and Neuropathology Data Set with diagnoses of normal cognition (NC; n = 234), mild cognitive impairment (MCI; n = 201), or AD dementia (n = 986). ADNP was defined as moderate to frequent neuritic plaques and Braak stageIII–VI. Ischemic Injury Scale (IIS) operationalized CVD. Joint modeling examined relationships among BMI, IIS, and ADNP in the overall sample and stratified by initial visit Clinical Dementia Rating score. Subject-specific random intercept for BMI was the predictor for ADNP due to minimal BMI change (p = 0.3028). Analyses controlling for demographic variables and APOE ɛ4 showed lower late-life BMI predicted increased odds of ADNP in the overall sample (p < 0.001), and in subjects with CDR of 0 (p = 0.0021) and 0.5 (p = 0.0012), but not ≥1.0 (p = 0.2012). Although higher IIS predicted greater odds of ADNP (p < 0.0001), BMI did not predict IIS (p = 0.2814). The current findings confirm lower late-life BMI confers increased odds for ADNP. Lower late-life BMI may be a preclinical indicator of underlying ADNP.

Keywords: Alzheimer’s disease, body mass index, cerebrovascular disease, neuropathology, obesity

DOI: 10.3233/JAD-161205

Journal: Journal of Alzheimer's Disease, vol. 57, no. 3, pp. 953-968, 2017